RESORB, “On-Demand Bioresorbable Optoelectronic System for in-Vivo and in-Situ Monitoring of Chemotherapeutic Drugs”, is a pathfinder EU-funded project that is being carried out by a consortium of five Universities/Institutes plus an Associated University (Bolzano) and that aims to develop an in-situ sensor of doxorubicin, a drug used in cancer treatment.
The implanted sensor would allow real-time monitoring of the drug concentration near the cancer tissue/site, allowing control of the drug administration to obtain the intended pharmacological effect, while avoiding excessive concentrations, when it becomes toxic. The main characteristics of the sensor are the selective detection of doxorubicin by measuring its fluorescence and the ability to trigger its disintegration after completing the function. This implies that the materials making the sensors biodegrade in the body, when “told to do so”, and that the materials and their degradation products are not harmful for the patient.
The sensor is made of several components, namely, an organic light-emitting diode (OLED) [fabricated at IT] able to excite the doxorubicin and induce its light emission (fluorescence), a battery (fabricated at Institut Mines-Telecom (IMT), in France, to power the OLED, being the emitted light (doxorubicin fluorescence) collected by an optical fiber (fabricated at the Universita di Pisa (UNIPI), Italy, and delivered under the skin. The intensity of the emitted light would then be measured on the patient's skin, allowing the determination of the local doxorubicin concentration.
A switch (designed at IMT), activated by radio frequency (RF), integrated into the sensor, would be used to light the OLED and allow the doxorubicin concentration determination at intended time points. To increase the doxorubicin detection sensitivity, a photonic cavity (fabricated at UNIPI) is also part of the sensor. The selectivity of the sensor relies on the use of a molecularly imprinted polymer substrate (fabricated at the Universita del Salento (UNISAL), Italy, that would be selective towards doxorubicin capture and presentation to the OLED light.
The sensor will be encapsulated by a polymeric material that will degrade upon a thermal chock (developed at UNISAL), exposing the sensor to the body fluids and initiating the sensor degradation. In-vivo tests in mice (carried out at Universitá Degli Study di Modena e Reggio Emilia (UNIMORE), Italy, will assess the biocompatibility of the device, its components, and degradation products, as well as the efficiency and rate of the triggered degradation.
Apart from the RF switch, all other components have already been fabricated and tested, and we are now moving toward their integration in a single device (the sensor). Though these components are already available in daily devices, the requirements posed by the need to be harmless for the patient and the need for the sensor degradation inside the body, at an intended time (avoiding the need for surgery for its removal), are the major challenges. If successful, the project is expected to have implications for the design of other implantable sensors. The envisioned sensor can also be modified to detect other biological molecules and drugs inside the body, providing continuous monitoring of their concentration.
The current methods to assess the concentration of drugs and other molecules in a living body rely on the analysis of body fluids (blood, urine, saliva, or sweat) in room-size labs. Besides the cost and time required to obtain a result, the determined concentrations may differ from those at specific body sites, namely at the cancer site, if we are interested in the assessment of an anticancer drug concentration.
Therefore, RESORB technology overcomes the limitations of traditional lab-based drug monitoring, paving the way for personalized, efficient, and safer treatments that redefine the future of medicine.
In photo: our researcher Filipa Pires (credits IT)
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